Is there any technique to give a metaball effect to the particles emitting from a UV Sphere?
You can't really emit particles directly from Meta Objects themselves, so you'll just have to fake it.
Just add a large Metaball overlapping your real UV sphere covering the actual emitter.
Adjust its size so it covers it entirely, or alternatively make the real UV Sphere emitter non-renderable.

Make sure it is named with a similar prefix to the particle Metaball (MBall## by default), so they actually interact with each other.


Off Topic - This is beyond the scope of the original question, but by user request for anyone interested, first demo image uses these settings below, relevant properties circled in screenshots.
Simple particle system with Newtonian Physics, pointing to a small Metaball object.
Under Velocity turn off Normal and increase Object Z slightly. In the Field Weights disable gravity so they &quot;float up&quot;, then add a texture to it.

Make the texture is Blend type, and turn off all influences except Size. Switch Mapping to Strand/Particle so it maps out &quot;through time&quot; rather than any spacial coordinate. Under the Color panel enable the Color Ramp and flip the default result so they shrink with age rather than grow.